A reader adds anecdotal evidence to the research:

I’ve fought the weight battle my whole life.  Now I’m down 37 pounds and seem to be maintaining at that new level. One of the reasons is marijuana. I’ve dieted frequently over the last couple of decades but no matter what I did I couldn’t seem to push below 239. It was as if my body just said “Thus far, no further.” I was tired of losing the battle, and my doctor was warning that diabetes could be in my future, so I concluded that I needed to shake things up.  I began by swapping marijuana for alcohol.  I’m now at 223, no longer technically obese, though I could certainly lose a few more pounds.

What’s stranger, though, is how easily I’m maintaining at 223. In the past the regaining of weight began almost immediately post-diet. Yes, I’m being reasonably disciplined, but not very. I’m smoking a moderate amount of legal medical weed once a day, in the evening when the work is done and I know I won’t be driving – same rules I had for alcohol consumption.  So far so good.  Not only is my weight down but my pulse and blood pressure are those of a much younger, fitter man than I’ve ever been.  I almost feel as if I’m cheating.

No idea why it works.  But it seems to.

Update from a reader:

“No idea why it works”? I do. Not drinking is the easiest way to lose and keep weight off. I would argue it has nothing to do with he/she replaced it with. My four-pack turned into an eight-pack when I stopped drinking for a few months. I’m very fit and exercise regularly. Those last five pounds that I couldn’t lose before, gone. They creep back over time if I drink even though I’m not a big drinker, 1-2 drinks/per week. When people who see me with my shirt off ask how I did it I simply say I quit drinking. The most common reply is “oh, I could never do that”.

Another writes:

Your post on lower rates of obesity and diabetes in regular marijuana users doesn’t surprise me at all, especially since I have seen so many cases of cannabinoid hyperemesis syndrome (also known as the “anti-munchies”) in my patients over the last three years.  This condition is characterized by periodic cycles of abdominal pain and vomiting in frequent marijuana users, and many of them have had extensive and costly medical testing without any definitive results.

The only definitive relief comes from abstaining from cannabis, although there are several unusual features of the condition (patients state that their nausea and pain are relieved by hot showers or baths) that help in diagnosis.  The mechanism of this disorder may simply be due to the brain “pushing back” against a constant flood of cannabinoids in the blood, similarly to the way chronic alcoholics or opiate addicts will experience tolerance and then withdrawal to those particular drugs.  Not every regular marijuana user develops this condition, but perhaps increasing rates of the condition are contributing to an overall decrease in obesity rates in this population.

A doctor is skeptical of the research we posted:

In general, I get frustrated with general reporting of scientific data.  It’s unfortunate that most people who write these articles 1) don’t understand science or research and 2) don’t understand statistics. Unfortunately, many scientists themselves don’t understand statistics, since the vast minority actually have masters degrees in clinical epidemiology.

So, what we get is post that links to a recent epidemiological study and claims that the data supporting cannabis and weight loss “are clear.” In fact, the study you referenced tells us nothing of the sort (despite the author’s claims in the discussion).  The cohort sampled showed a direct overlap between patients who used tobacco and those who used marijuana.  I don’t care if the epidemiologists claim to be able to use fancy statistical methods to control for tobacco use, the fact is that they can’t actually do that.  All this study tells us is that there MAY be an association between cannabis and weight loss, but frankly drawing that conclusion is a stretch.